Interior grinding machine for grinding out bores accurately



Sept. 8, 1931. K. JUNG 1,822,222

INTERIOR GRINDING MACHINE FOR GRINDING-OUT BORES ACCURATELY Filed June 5, 1929 s Sheets-Sheet 2 .7/2 vezzZon Sept. 8, 1931.

K. IUNG INTERIOR GRINDiNG UACH INE FOR GRINDING-OUT BORES ACCURATELY a Sheets-Sheet 3 Filed June s, 1929 \v/llll/lllllll/ v/yapll/li Patented Sept. 8, 1931 UNITED STATES PATENT. OFFICE KARL JUNG, OF BERLIN, GERMANY Application filed .l'une 3, 1929, Serial No. 868,061, and in Germany May 7, 1927.

This invention relates to an interior grinding machine for grinding out bores accurate- 3 In grinding out accurately dimensioned bores on interior grinding machines care is taken to sub-divide the grinding process into a rough grinding and a finishing inding operation. The tool namely which e ects the rough grinding becomes used up relatively I quickly so that if it is desired to perform the finishing grinding with the same tool it is necessary to re-measure and re-set again. On this account it has already been proposed after rough grinding a bore, to dress the grind ing tool so that the grinding surface is located in a definite position opposite the bore, and since, upon the finishing grinding operation, there is scarcely any question of wear of the grinding disc, a completely accurate bore may be obtained with the dressed grinding disc without special re-measurement.

The present invention relates to a machine of this character, but has for its object to simplify the known construction of such machines, in that the work-piece to be treated and the dressing tool for the grinding disc are located in a revolving head.

The manner of working of the apparatus is accordingly such that the work-piece clamped in the revolving head is worked upon initially up to a definite degree by the grinding tool inserted into the bore. Then the revolving head and grinding tool separate, the revolving head is changed over and now brings the dressing device into operative position opposite the grinding disc. The grinding disc is then set to an accurate measure and therevolving head again brought into the starting position, re-dressed tool the finishing operation of the work-piece can take place.

The changing over of the revolving head is carried out preferably according to the invention in a hydraulic manner. It is already lmown, in grinding machines or machine tools of'this character to provide revolving heads, which carry either different tools or difl'erent work-pieces, which enter into operation one after the other. According to the present invention however a dressing device 'the framework of the machine.

is located in a revolving head. adjacent a work-piece to be treated, so that the grinding tool alternately inthe one position of the revolving head serves as a tool, in the other position of the revolvinghead is itself worked "upon by the dressing tool.

The'drawings illustrate an embodiment of the invention by way of example, and in which Figure 1 is a front elevation ofa grinding machine which is embodied according to the invention with the omission of all portions not pertaining to the invention,

Figure 2 is a plan of Figure 1, while Figure 3 illustrates a side view.

Figures 4 and 5 illustrate the hydraulic changing device for the revolving head in longitudinal section and in cross-section, Fig. 4 being taken on line H of Fig. 5.

In the drawings, the numeral 1 designates Upon this is mounted the work-piece carrying slide 2 slidable longitudinally of the machine and upon the longitudinal slide is mounted a transverse slide 3 slidable transversely, upon which the bearing 4' for the grinding disc carrying spindle 6 is=located. The grinding disc 5 can then, with the aid of the cross supports 2 and 3 and with the aid of known mechanism, not illustrated in the drawings, be adjusted longitudinally and transversely on the table. The drive of the grinding disc 5 takes place with the aid of a motor 7, the shaft of which drives a belt pulley 8, which in turn by means of a belt 9 sets the driving pulley .10, secured upon the shaft 6, for the grinding spindle into rotation.

Opposite the grinding disc is provided so that now with the the revolving head upon the table 1 of the machine. This consists of an outer, preferably, two-part,-fixed bearing portion 11 anda portion 12 rotating therein. In the inner rotating portion 12 of the revolving head-is mounted a rotating spindle 13 which carries at its end facing the grinding tool 5 the chuck 14 for holding the work-piece. At the opposite end in the rear of the revolving head is located the driving pulley 15 upon the spindle 13. Moreover a further pulley 15a isloosely mounted in the rotating portion 12 and of the same diameter as the pulley 15. The drive of the spindle 13 and the chuck 14 carrying the work-piece takes place through the belt 16, which runs over two guide rollers 17 and 18 and according to the position of the portion 12 either over the loose pulley 15a or over the driving pulley 15, and is set into movement by means of a driving pulley, not illustrated in the drawings, at the lower end of the machine frame. In the position of the revolving head illustrated in Figure 1 the belt 16 runs over the pulley 15a and consequently no rotation of the belt pulle 15 occurs. If however the revolving hea is turned through 180 then the belt 16 runs over the belt pulley 15, so that the shaft 13 and the chuck 14 rotate.

Upon the rotating portion 12 of the revolving head is located a carrier 19 oppositely disposed to the spindle 13 by 180. On this carrier are provided two guide rods 20 and 21 upon which a holder 22 for a dressing tool, for example a diamond 23, is slidably andadjustably provided.

The revolving head can, by any desired and manifold known means and with the aid of an also known control be rotated in ofi'set manner through 180, so that in one position of the work-piece carrier 14 the grinding disc 5 is in operative position with respect to the work-piece and in the other position with respect to the dressing tool 23. For changing over the revolving head any desired means, as stated, may be employed. Preferably for this purpose a hydraulic form of drive is employed, as illustrated in Figures 4 and 5. According to this embodiment the inner rotatable portion 12 of the revolving head carries a toothed crown 24, which rests in engagement with a toothed wheel 25 upon the shaft 26. The shaft 26 further carriers a toothed wheel -27, which rests in engagement with a piston 28 formed on the one side with a rack, so that by sliding the piston in its axial direction the toothed wheel 27 and therewith the shaft 26 rotates further the toothed wheel 25 and the revolving head 12. The piston 28 is guided in a sleeve 32 and moves in a cylinder 29, in which said sleeve is arranged. The length of the cylinder is so dimensioned, that upon movement of the piston from one end of the cylinder to the other the revolvin head is rotated about 180. Attached to file cylinder ends are provided fluid conduits 30 and 31, in which regulated valves are inserted in known manner, which are not illustrated in :the drawings and by the control of which it is effected that oil flows alternately through the lead 30 or 31 and thereby the piston is moved towards one or the other direction.

Themachine operates accordingly in the followin manner:

A wor -piece is mounted in the chuck 14 and the machine is set into operation. The

feeding mechanism not illustrated in the drawings now moves the longitudinal slide 2 with the grinding disc towards the left in Figure 1, so that the grinding disc enters the bore of the work-piece to be ground out and moves axially to and fro Within the same. At the same time the adjustment of the tool 5 takes place by sliding of the transverse slide 3 upon the longitudinal slide 2. As this movement represents the usual manner of grinding bores and the mechanisms for moving the slides are known, closer description and illustration is not necessary. As soon as the rough grinding of the workpiece is finished the grinding tool 5, is moved by sliding of the longitudinal slide 2 out of the work-piece and at this stage by changing over the fluid lead a rotation of the revolving head takes place, so that the work-piece assumes the inoperative position, whereas the dressing tool 23 comes into operative position with respect to the grinding disc 5.

Upon subsequent renewed movement of the grinding disc 5 longitudinally with the aid of the slide 2 and subsequent transverse adjustment with the aid of the slide 3 the grinding disc is dressed by means of the accurately adjusted dressing tool 23.

Then further reverse movement of the revolving head takes place. The work-piece now faces again the grinding tool 5 and the latter is so dressed by the dressing tool and brought to such a diameter that it simply requires with the aid of the slide 2 to be moved axially with respect to the work-piece and inserted therein, in order to grind the accurate internal diameter of the latter. As soon as the tool 5 has emerged again from the work-piece and arrived at the position illustrated in Figure 5 the operation is finished, the work-piece can be de-chucked and vreplaced by a further one.

I claim:

1. An internal grinding machine for accurately grinding out bores, comprising a frame; a tool holder mounted on said frame and including a rotatable spindle having a grinding tool mounted thereon; a revolving head mounted on said frame, said head having a chuck for holding the work-piece and a dressing device for the grinding tool; and means for revolvin the head so that alternately a dressing of? the grinding tool and a grinding of the bore of the workpiece takes place, said holder and head being slidably arranged relatively to each other.

2. Internal grinding machine for accurately grinding out bores, comprising a frame; a tool holder mounted on said frame and including a rotatable spindle having a grinding tool mounted thereon; a revolving head mounted on said frame, said head having a chuck for holding the workpiece and a dressing device for the grinding tool; and hydraulic means including a toothed crown and a rack rod connected to a piston for revolving the head so that alternatel a dressing of the grinding tool and a of the bore of the workpiece takes 'p ace, sai holder and head being slidably arranged relatively to each other.

3. Internal grinding machine for accurately grinding out bores, comprising a frame; a tool holder mounted on said frame and including a rotatable spindle having a grinding tool mounted thereon; a revolving head mounted on said frame, said head having a chuck for holding the workpiece and a dressing device for the grinding tool; and hydraulic means for revolvin the head so that alternately a dressin o the grinding tool and a grinding of the ore of the workpiece takes place, said holder and head being slidably arranged relatively to each other.

In testimony whereof I afix m signature.

KAR J UN G.

ining 

